@Richard *******
what is your true intention?
*** do you want to enjoy a holiday of longer than 90 days? Then get the multi entry Tourist visa. This visa can get you up to almost 9 months in Thailand
*** do you want a holiday longer than 90 days? Then get the 90-days single entry Non-Imm-O visa in your home country, enter Thailand, exit before the 90 days are over, enter visa-exempt and get stamped in for 60 days and extend for 30 days - 90+60+30 = 180 days
*** you could enter visa-exempt, get stamped in for 60 days, apply for the “change of visa type” to the 90-days Non-imm-O visa. But never go for the extension, exit Thailand before the 90 days stay permit expires. Re-entry and try that game, again. I think your Immigration officer was right – you can’t apply for the “change of visa type” in a consecutive manner. You got one shot in a calendar year . . . . .so the correct answer is: You can do the "change" every calendar year, again and again . . .did you read the requirements for this? You need a 3- 6-months rental contract, and you need 800.000 THB sitting in your Thai bank account. In case you ever had an overstay, you cannot apply for the "change"